{"id":"CVE-2025-5270","title":"In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled","summary":"In certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability was fixed in Firefox 139 and Thunderbird 139.","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N","cwe":["CWE-319"],"vendor":"mozilla","product":"firefox","affected":["firefox < 139.0"],"patched":["firefox 139.0"],"published":"2025-05-27","updated":"2026-09-30","sourceUpdated":"2026-09-30T18:10:00.190","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-5270","references":[{"url":"https://bugzilla.mozilla.org/show_bug.cgi?id=1910298","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-42/","label":"security@mozilla.org"},{"url":"https://www.mozilla.org/security/advisories/mfsa2025-45/","label":"security@mozilla.org"}],"tags":["nvd"],"epss":0.00286,"epssPercentile":0.1902,"ingestedAt":"2026-09-30T18:17:24.440Z","slug":"CVE-2025-5270","body":"## Overview\n\nIn certain cases, SNI could have been sent unencrypted even when encrypted DNS was enabled. This vulnerability was fixed in Firefox 139 and Thunderbird 139.\n\n## Affected\n\n- `firefox < 139.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `firefox 139.0`","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}